Actuators, such as motors or muscles, produce forces that are used to move objects. Because they are essential in creating motion for almost every product or device that moves, actuators are ubiquitous and are currently dominated by the traditional electromagnetic motor, a device that has not benefited from a revolutionary innovation within the last 100 years. Though motors and other current actuation technologies are sufficient for some motion needs, they have significant limitations for niche applications such as prosthetics and robotics, which may require a more compact and efficient source of motion production. Specifically, problems with previous actuation methods for such applications include high costs, heavy weight and bulkiness, inefficient battery use, and noisiness.
The quest for efficient, powerful and lightweight actuation technologies has recently focused on the use of dielectric elastomers for creating so-called “artificial muscles” [“Artificial Muscles”, Scientific American, October 2003]. Although these materials are capable of matching the metrics of biological muscle (Pelrine et al. 2000), previous fabrication techniques and polymer configurations require extremely high voltage and the use of external structures to harness the mechanical power output. Accordingly, there is a continuing need to provide improved actuators that have improved stress, strain and speed characteristics. In addition, there is a need to provide novel actuator configurations that allows direct use of mechanical power output (force/displacement) and that reduces actuation voltage.